1. Field of the Invention
The present invention relates to a forming method of forming tungsten silicide (WSi.sub.x) on polysilicon or single crystal silicon in manufacturing a semiconductor device, and to a semiconductor manufacturing method and a semiconductor device to which this method is applied.
2. Background Art
It has become usual that, in a semiconductor device, a tungsten silicide (WSi.sub.x) film is formed on a polysilicon or single crystal silicon included in a silicon wafer. The tungsten silicide (WSi.sub.x) has a possibility of exhibiting a low electrical resistance. On the other hand, the film forming process of the tungsten silicide is very much influenced by a surface condition of a polysilicon or a silicon. This tends to cause a process failure such as peeling of a silicide film, so that stable depositing of a silicide film having superior characteristics is difficult. This is a problem in the application to the mass production. Hereinafter, in the present invention, a technical term of the silicon wafer is used to mean either a polysilicon or a single crystal silicon.